In injection molding machines, there is an injecting screw comprising a piston which is acted upon by a pressure of about 120 to 200 bar at the injection stroke, whereas when filling the injection molding machine, a pressure of about 5 through 10 bar is applied. In order to get such different pressure settings, generally a pressure limiting arrangement consisting of a main relief valve and a proportional pilot valve is used, the setting thereof is adjusted electrically. The accuracy of pressure setting of the pilot valve determines the accuracy of the whole arrangement. In view of the large range to be covered from 5 to 200 bar, it is not possible to adjust the pilot valve really onto the desired pressure setting, if same is near to the limits of the range. Since it is very important to hold the injection pressure precisely, the type of pilot valve is selected in view of the higher pressure value of 120 through 200 bar. Such a pilot valve does not work precisely for the filling pressure in the region of about 5 to 10 bar.